A vcry important question raised by Dcrck Parfit in the part 0i` Reasons and Persons which dcals with population ethics is how t0 compare thc future outcomes 0i` those policies which differ in thc way they afTcct population growth} Such comparisons arc complicated by the fact that thcsc 0utcomcs may differ not only in thc avcragc Icvcls 0f well-being they gcncratc but also in thc identity and number 0i` thc persons who cxist.

Challenging, with several powerful arguments, some of our deepest beliefs about rationality, morality, and personal identity, Parfit claims that we have a false view about our own nature. It is often rational to act against our own best interersts, he argues, and most of us have moral views that are self-defeating. We often act wrongly, although we know there will be no one with serious grounds for complaint, and when we consider future generations it is very hard to avoid conclusions (...) that most of us will find very disturbing. (shrink)

Suppose one sets up a sequence of less-and-less valuable objects such that each object in the sequence is only marginally worse than its immediate predecessor. Could one in this way arrive at something that is dramatically inferior to the point of departure? It has been claimed that if there is a radical value difference between the objects at each end of the sequence, then at some point there must be a corresponding radical difference between the adjacent elements. The underlying picture (...) seems to be that a radical gap cannot be scaled by a series of steps, if none of the steps itself is radical. We show that this picture is incorrect on a stronger interpretation of value superiority, but correct on a weaker one. Thus, the conclusion we reach is that, in some sense at least, abrupt breaks in such decreasing sequences cannot be avoided, but that such unavoidable breaks are less drastic than it has been suggested. (shrink)

According to the discontinuity view we can have a (lower) pleasure which, no matter how often a certain unit of it is added to itself, cannot become greater in value than a unit of another (higher) pleasure. All recent adherents of this view seem to rely basically on the same sort of reasoning which is referred to here as the preference test. This article presents three arguments, each of which indicates that the inference from the preference test to the discontinuity (...) view is not conclusive. (shrink)

Suppose one sets up a sequence of less-and-less valuable objects such that each object in the sequence is only marginally worse than its immediate predecessor. Could one in this way arrive at something that is dramatically inferior to the point of departure? It has been claimed that if there is a radical value difference between the objects at each end of the sequence, then at some point there must be a corresponding radical difference between the adjacent elements. The underlying picture (...) seems to be that a radical gap cannot be scaled by a series of steps, if none of the steps itself is radical. We show that this picture is incorrect on a stronger interpretation of value superiority, but correct on a weaker one. Thus, the conclusion we reach is that, in some sense at least, abrupt breaks in such decreasing sequences cannot be avoided, but that such unavoidable breaks are less drastic than it has been suggested. (shrink)